The effect of the prepartum diet of the cow on the vitamin A reserves of her newborn offspring

Feeding vitamin A at the rate of a million U.S.P. units daily to individual dairy cows in the latter stages of gestation augmented significantly the vitamin A concentration in the blood and the livers of their newborn calves, but pasture grazing, providing an abundance of carotene in the prepartum diet of the dams, failed to effect an increase over that observed in calves from dams restricted to a standard winter ration. The explanation for these divergent results is obscure, but it is suggested that the placental membrane may be more permeable to the ester form of vitamin A than to the alcohol form. This high initial vitamin A reserve in the newborn calf should have practical value in the maintenance of its postnatal health.     

Stability of common biochemistry analytes in equine blood stored at room temperature

Reasons for performing study: Time delays between collection of blood samples and biochemical analysis of equine blood are unavoidably common in equine practice. The effect that delays may have on the accuracy of results of blood biochemical analyses is not well established. Hypothesis: Delays in processing of blood of up to 72h results in alterations in measured levels of common biochemical analytes that are of potential clinical relevance. Separation of serum prior to storage is protective against the effects of time delays. Methods: Samples of clotted blood, separated serum and oxalate fluoride plasma from 20 horses were stored and analysed at 0, 24, 48 and 72 h. Graphical exploration of each analyte was undertaken. General linear models with fixed effects were fitted for the whole blood data. The mean bias and 95% limits of agreement were calculated, using bootstrapped data, to assess agreement between pairs of samples analysed at 0 h and other time points. Bland‐Altman plots were used to explore general trends in the data. Paired t tests were used to compare the results from whole blood and separated serum. Results: Delays in processing equine blood resulted in significant increases in measured concentrations of aspartate aminotransferase, creatine kinase, lactate dehydrogenase, total bile acids and magnesium. A significant decrease in concentration was identified for glucose (serum and oxalate fluoride preserved plasma). Separation of serum immediately following clot formation resulted in nonsignificant increases in accuracy for some analytes. Conclusions and practical significance: Delays in processing of blood samples may result in biochemical changes of clinical relevance in individual cases; however, in the majority of cases, where delays are only a few days and a number of analytes are assessed concurrently, delays are unlikely to have an effect on the interpretation of results. Separation of serum following clot formation is of limited benefit. Clinical samples in which a delay in processing has occurred may be interpreted with reference to the data presented.     

Partial Right Ventriculectomy Using the Incised Patch Technique to Treat Double Chambered Right Ventricle and Chylothorax in a Cat

Objective— To report successful surgical treatment of double chambered right ventricle (DCRV) in a cat.
Study Design— Clinical report.
Animals— Cat with DCRV.
Methods— DCRV was diagnosed in a 5-month-old male Maine Coon cat using echocardiography and angiocardiography. At 2 years, despite medical therapy, chylothorax developed. A section of the right ventricular free wall that spanned the fibromuscular obstruction was excised under total venous inflow occlusion (TVIO) using the incised pericardial patch technique.
Results— Short-term recovery was complicated by return of chylothorax but this resolved after thoracocentesis and diuretic therapy. Three years after surgery, the cat is free of clinical signs and no longer on any medical therapy.
Conclusions— Partial right ventriculectomy can be performed under TVIO through an incised pericardial patch.
Clinical Relevance— DCRV in cat can be successfully treated by partial right ventriculectomy performed under TVIO through an incised pericardial patch.     

Synthesis and detection of toltrazuril sulfone and its pharmacokinetics in horses following administration in dimethylsulfoxide

Triazine-based antiprotozoal agents are known for their lipophylic characteristics and may therefore be expected to be well absorbed following oral administration. However, although an increase in lipid solubility generally increases the absorption of chemicals, extremely lipid-soluble chemicals may dissolve poorly in gastrointestinal (GI) fluids, and their corresponding absorption and bioavailability would be low. Also, if the compound is administered in solid form and is relatively insoluble in GI fluids, it is likely to have limited contact with the GI mucosa, and therefore, its rate of absorption will be low. Based on the above considerations, we sought a solvent with low or no toxicity that would maintain triazine agents in solution. As the oral route is most preferred for daily drug therapy, such a solvent would allow an increased rate of absorption following oral administration. In present study, it was demonstrated that dimethylsulfoxide (DMSO) increased the oral bioavailability of toltrazuril sulfone (Ponazuril) threefold, relative to oral administrations of toltrazuril sulfone suspended in water. The cross-over study of toltrazuril sulfone formulated in DMSO indicated that the absolute oral bioavailability of toltrazuril sulfone in DMSO is 71%. The high bioavailability of the DMSO-preparation suggests that its daily oral administration will routinely yield effective plasma and cerebral spinal fluid (CSF) concentrations in all horses treated. Also, this improved formulation would allow clinicians to administer loading doses of toltrazuril sulfone in acute cases of Equine Protozoal Myeloencephalitis. Another option would involve administration of toltrazuril sulfone in DMSO mixed with feed (1.23 kg daily dose) meeting the US Food and Drug Administration (FDA) recommendations for the levels of DMSO permissible in pharmaceutical preparations.     

Clinical field study to evaluate the efficacy and safety of the amino-acetonitrile derivative, monepantel, compared with registered anthelmintics against gastrointestinal nematodes of sheep in Australia

Objective   To determine the efficacy of monepantel, a developmental compound from the amino-acetonitrile derivative class of anthelmintics, against field infections of gastrointestinal nematodes in sheep.
Procedures   Comparisons of efficacy (using standard faecal worm egg count reduction tests) and safety (on the basis of visual observations) were made in a large-scale field study in Australia, between groups of sheep treated with either an oral solution of monepantel or a registered anthelmintic. The sheep were naturally infected with the major gastrointestinal nematode genera present in Australia.
Results   The post-treatment efficacy results for monepantel were: at 7 days (±1 day) efficacy was >98%; at 14 days (±1 day) it was generally close to or >99%; and at 21 days (±1 day) efficacy was consistently >99%. A high proportion of the targeted nematode populations were confirmed as being resistant to one or more of the currently available anthelmintic classes.
Conclusions   Monepantel when used under field conditions at a minimum dose rate of 2.5 mg/kg was highly effective against mixed-genus natural field infections of the major gastrointestinal nematode genera including Haemonchus , Teladorsagia ( Ostertagia ), Trichostrongylus , Nematodirus , Chabertia and Oesophagostomum . This result included efficacy against some populations resistant to the currently available broad-spectrum anthelmintics. Few Cooperia spp. were present to allow confirmation of efficacy against this genus. On no occasion after treatment did any commercial anthelmintic-treated groups have significantly lower faecal egg counts than the monepantel-treated groups. Monepantel was safe for the target animals and human operators when used in a field situation.     

Integrating practical, regulatory and ethical strategies for enhancing farm animal welfare

OBJECTIVE: To provide an integrated view of relationships between assessment of animal welfare. societal expectations regarding animal welfare standards, the need for regulation, and two ethical strategies for promoting animal welfare, emphasising farm animals. APPROACH: Ideas in relevant papers and key insights were outlined and illustrated, where appropriate, by New Zealand experience with different facets of the welfare management of farm animals. CONCLUSIONS: An animal's welfare is good when its nutritional, environmental, health, behavioural and mental needs are met. Compromise may occur in one or more of these areas and is assessed by scientifically-informed best judgement using parameters validated by directed research and objective analysis in clinical and practical settings. There is a wide range of perceptions of what constitutes good and bad welfare in society, so that animal welfare standards cannot be left to individual preferences to determine. Rather, the promotion of animal welfare is seen as requiring central regulation, but managed in a way that allows for adjustments based on new scientific knowledge of animals' needs and changing societal perceptions of what is acceptable and unacceptable treatment of animals. Concepts of 'minimal welfare', representing the threshold of cruelty, and 'acceptable welfare', representing higher, more acceptable standards than those that merely avoid cruelty, are outlined. They are relevant to economic analyses, which deal with determinants of animal welfare standards based on financial costs and the desire of the public to feel broadly comfortable about the treatment of the animals that are used to serve their needs. Ethical strategies for promoting animal welfare can be divided broadly into the 'gold standard' approach and the 'incremental improvement' approach. The first defines the ideal that is to be required in a particular situation and will accept nothing less than that ideal, whereas the second aims to improve welfare in a step-wise fashion by setting a series of achievable goals, seeing each small advance as worthwhile progress towards the same ideal. 'Incremental improvement' is preferred. This also has application in veterinary practice where the professional commitment to maintain good welfare standards may at times conflict with financial constraints experienced by clients.